1. Field of the Invention
The present invention relates generally to a voice warning system for an automotive vehicle, and more particularly to a voice volume controller provided for the voice warning system whereby the voice volume is automatically changed according to the degree of urgency of warning information on various vehicle operating conditions. In this case, the driver is informed of various operating conditions, in voice form, according to the car-radio sound volume as adjusted by driver preference in addition to the degree of urgency.
2. Description of the Prior Art
Heretofore, as means for informing the driver of various vehicle operating conditions, there have been used various meters with pointers and various warning indication lamps. In addition, recently, there have appeared vehicles in which a computer is mounted so as to display digitally various vehicle operating conditions whenever the driver depresses pushbuttons to obtain the vehicle conditions. That is to say, in these devices, the driver is informed of the vehicle conditions through the sense of sight. On the other hand, as devices by which the driver is informed through the sense of hearing, there have been used various devices which produce a simple warning sound such as buzzer or chime.
Although these conventional warning devices which depend upon the sense of sight have the advantage that a number of vehicle conditions can be displayed at the same time, it is comparatively difficult to attract the driver's attention and to give the driver complicated information. Also, in the case of the conventional devices which depend upon the sense of hearing, it is difficult to inform the driver of different items of information, even if the device can attract the driver's attention.
Therefore, recently, various voice warning systems have come to be used for vehicles by which the driver can hear various vehicle operating conditions such as the distance traveled detected by a trip meter, the amount of fuel consumed and so on, in voice form.
When such a device as described above is used for an automotive vehicle, it is possible to attract the driver's attention well and also to inform the driver of relatively complicated vehicle operating conditions without any difficulties. In this case, however, since there are various kinds of information, for example, information being required frequently or occasionally, information being important or less important, or information being urgent or less urgent, if the information is always indicated to the driver at a constant sound level, there has arisen a problem that the driver feels noisy when the sound level is too high and fails to hear when too low.
Therefore, there is a need for a voice warning system for an automotive vehicle by which the driver can always hear the warning voice at an appropriate sound level according to the kind of warning information.